Poly (lactic-co-glycolic acid) as a controlled release delivery device

Poly (lactic-co-glycolic acid) (PLGA) is a biodegradable polymer used to make resorbable sutures, and is also used in other applications in tissue engineering. Being an artificial polymer, its degradation rate can be tailored to suit its application. It can be easily moulded into structures with suitable mechanical strength and degrades into relatively harmless products in the body. Its adjustable degradation rate also makes it a potentially excellent controlled release delivery device. However, the functionalization of PLGA with bioactive molecules usually requires extensive chemical modification. Chemical modification may compromise the mechanical strength of PLGA and inactivate the bioactive molecules. In this paper, a study is done to investigate the coating of an angiogenic factor on unmodified PLGA suture substrates for the differentiation of human mesenchymal stem cells (hMSC) into endothelial cells (EC). The results show that the method used to anchor vascular endothelial growth factor (VEGF) onto the PLGA surface can enable the gradual release of VEGF from the substrate into solution to induce the differentiation of hMSCs into ECs. Thus, this method can potentially be used to coat PLGA materials like sutures, meshes and scaffolds, rendering them functional as effective controlled release delivery devices for a wide range of bioactive molecules.